When viewing The Great Unconformity,
The result of a vast denudation,
One feels a new sense of enormity …
And above it lie critters crustacean!
Life during this wild explosion,
For armor, developed affinity.
Whence the new ions? Erosion!
Gooey life — meet alkalinity!

Through an ancient looking-glass,
Perhaps you’d see more H2 gas,
And if with denser gas collided,
Greater greenhouse warmth provided.
With faint young sun, would this suffice
To maintain water and not ice?
And when methanogens arrive?
This old debate is much alive.

Graduate students, microbe goo …
What is it that links the two?
It seems that both life forms are found
Where electron donors (food) abound!
Sed rates, organic stuff control
Cell distribution on the whole.
New techniques birth a new notion:
Sub-seafloor mass, the same as ocean.

A pigeon’s got cells in its brain
That link up with its inner ear.
Despite any wind, fog, or rain,
These talented birds, they can steer!
The magnetic field is their guide
(At bygone reversals: a rumpus?)
A field vector’s measured inside
A bird-brain equipped with a compass!

Giant fleets the oceans trawl,
Gasping fish they skywards haul.
Not just critters do they move,
But sediments they push and groove …
Ten times greater their extent
Than the land that farmers dent!
What will come of shelf slopes now,
Underneath the deep-sea plough?

Earth’s magnetic field lines are almost vertical near the poles. The dancing lights of the aurora borealis are the result of interactions between Earth’s magnetic field, atmosphere, and energetic particles from the sun. Image: NASA’s Goddard Space Flight Center.

Phytoliths — mineral particles formed by plants — found in the teeth of one of our ancient ancestors. Photo: AG Henry, Nature, 2012.

Across a mixed landscape, Au. sediba plods
Sometimes on two feet, and sometimes on four,
Munching on fruits and leguminous pods,
Nuts and some seeds … C3 foods galore!
They did have a choice (so coprolites hint);
Lush grasses, fat grazers were also around,
But in these old ancestors (destined for flint?)
New clues, new stories have just now been found.
With lasers and microscopes, old dental plaque —
Tiny, stuck phytoliths show a rich diet!
Scratched-up enamel, it all brings us back
To lives of these creatures that have long been quiet.
What wonders are learned from plaque and from feces,
History bound in compounds beneath!
So, we should say to that wonderful species:
Thanks for not brushing your teeth!